Stable molybdenum (Mo), thallium (Tl), and uranium (U) isotope ratios were determined in a suite of samples from the 1959 Kilauea eruption and from Kilauea Iki lava lake with the aim of understanding the effects of igneous differentiation on these isotope systems. The samples range from olivine cumulate with MgO up to 27% to internal differentiates with MgO less than 3%, representing a tholeiitic differentiation series. Molybdenum, Tl, and U behave incompatibly during differentiation, and Mo and U isotope ratios do not systematically vary amongst the different samples. δ⁹⁸Mo values range from −0.17 to −0.31‰ and δ²³⁸U values range from −0.20 to −0.38‰. Most individual analyses for both isotope systems overlap within measurement uncertainty (± ~0.7 and ~ 0.6, respectively). Mean δ⁹⁸Mo and δ²³⁸U values are −0.22 ± 0.08‰ (2σ) and − 0.29 ± 0.09‰ (2σ), respectively, which overlap with Pacific mid ocean ridge basalt (MORB). In contrast, Tl isotopes show small but resolvable variations, with ε²⁰⁵Tl ranging from +1.20 to −1.38. The most negative ε²⁰⁵Tl values are confined to some of the lowest [Tl] samples, but the ε²⁰⁵Tl values do not otherwise vary smoothly with MgO or [Tl]. Possible mechanisms for thallium isotope fractionation are considered (e.g., degassing, water leaching, sulfide fractionation) but none are found to be satisfactory. Overall, the lack of resolvable variation in the Mo and U isotope systems and the small magnitude of heterogeneity in the Tl isotope system indicate that differentiation in tholeiitic systems is unlikely to be a major contributor to global variation in these isotope systems.

在1959年基拉韦厄火山喷发和基拉韦厄伊基熔岩湖的一组样品中确定了稳定的钼（Mo），th（Tl）和铀（U）同位素比，目的是了解火成分化对这些同位素系统的影响。样品的范围从橄榄石累积的MgO高达27％到内部分化的MgO少于3％，代表了分化的系列。钼，Tl和U在分化过程中的行为不兼容，并且不同样品中的Mo和U同位素比没有系统地变化。δ ^98个沫值的范围从-0.17到-0.31‰和δ ²³⁸的U值的范围从-0.20到-0.38‰。两种同位素系统的大多数单独分析都在测量不确定度内重叠（分别为±〜0.7和〜0.6）。平均δ⁹⁸ Mo和^δ238 U值分别为-0.22±0.08‰（2σ）和-0.29±0.09‰（2σ），与太平洋中部洋脊玄武岩（MORB）重叠。与此相反，铊同位素显示小，但可分辨的变化，与ε ²⁰⁵铊范围从1.20至-1.38。最负ε ^205个T1值被限制在一定的最低[铊]样品，但ε ²⁰⁵Tl值不会随MgO或[Tl]平滑变化。考虑了al同位素分级分离的可能机理（例如脱气，水浸，硫化物分级分离），但没有一个令人满意。总体而言，Mo和U同位素系统缺乏可分辨的变化，而T1同位素系统中的异质性较小，这表明可塑体系的差异不太可能是这些同位素系统总体变化的主要因素。